- Previous use of an integrase inhibitor (ie raltegravir) or a CCR5 inhibitor (ie maraviroc, vicriviroc). Use of raltegravir for non-treatment failure indications such as intensification and toxicity switches is allowed, provided that 1) virologic suppression was maintained before, during and after raltegravir treatment and 2) the patient has not received raltegravir treatment in the 6 months prior to study entry.